Roaring Fork River below Maroon Creek near Aspen
Roaring Fork River · Rockies · USGS gage 09076300
Coldwater (summer mean 11.9°C — prime coldwater).
Water
52°F
Flow
140 cfs
Air
57°F
Sky
54%
Pressure
29.88 in
Wind
4 mph
Predicted hatches · 2026-09-15
PredictedBlue-Winged OliveBaetis spp.0.45
Predicted by conditions; no reports yet. water 11.3°C (52°F) is cooling past the prime band (6-11°C); shoulder of the season; 7 days sustained ≥4°C; watch midday, especially overcast afternoons.
flies: BWO Sparkle Dun #18-22, RS2, Pheasant Tail #18
PredictedMidgeChironomidae0.39
Predicted by conditions; no reports yet. water 11.3°C (52°F) is cooling past the prime band (1-10°C); shoulder of the season; 7 days sustained ≥0°C; watch midday, especially cold months.
flies: Zebra Midge #18-22, Griffith's Gnat, Disco Midge
PREDICTED from the first-principles model only. Report-confirmed signal (fly-shop & forum reports) is the next milestone.